The 2nd U.S. Circuit Court of Appeals on Thursday said the plaintiff Ernesto Espinoza did not show that JPMorgan’s board was grossly negligent or engaged in bad faith in probing the losses and whether bank officials publicly downplayed them, and in deciding not to sue the people involved.

JPMorgan suffered losses in its chief investment office because of derivative bets by Bruno Iksil, known as the London Whale because of the size of his wagers.

Dimon received criticism soon after the scandal broke for calling media reports about the losses a “tempest in a teapot.”

Writing for the New York-based appeals court, Chief Judge Robert Katzmann said JPMorgan conducted an “exhaustive” London Whale probe that led to many changes sought by Espinoza including pay cuts, clawbacks and improved controls.

Citing applicable Delaware law, Katzmann also called courts “ill-suited” to second-guess board decisions, and said New York-based JPMorgan was not required to explain to Espinoza point-by-point why it did not do more.

“Espinoza has not sufficiently rebutted the presumption that JPMorgan’s board acted in good faith in responding to his demand letter,” Katzmann wrote for a three-judge panel.

George Aguilar, a partner at Robbins Arroyo representing Espinoza, said: “We’re naturally disappointed by the court’s opinion, but respectful of its view.” No decision has been made on whether to appeal.

The appeals court had in June upheld the March 2014 dismissal of Espinoza’s lawsuit by U.S. District Judge George Daniels.

It revisited the case after asking the Delaware Supreme Court to advise how to evaluate shareholder challenges to the scope of board investigations.

JPMorgan paid more than $1 billion and admitted wrongdoing to settle U.S. and British probes into the London Whale matter.

Former JPMorgan traders Javier Martin-Artajo and Julien Grout have been charged with hiding losses linked to Iksil, a French national. Iksil is cooperating with prosecutors.